Charles V. neither signed nor opposed the edict of
Speier. He had shortly before fallen out with Clement VII., because
this Pope released King Francis I. from the hard conditions of peace
imposed upon him after his defeat at Pavia, June 26, 1526, and placed
himself at the head of a Franco-Italian league against the
preponderance of Austria the Holy League" of
Cognac, May 22, 1526). The league of the Emperor and the Pope had
brought about the Edict of Worms; the breach between the two virtually
annulled it at the Diet of Speier. Had the Emperor now embraced the
Protestant doctrines, he might have become the head of a German
imperial state church. But all his instincts were against
Protestantism.

His quarrel with the Pope was the occasion of a
fearful calamity to the Eternal City. The Spanish and German troops of
the Emperor, under the lead of Constable Charles de Bourbon, and the
old warrior Frundsberg (both enemies of the Pope), marched to Rome with
an army of twenty thousand men, and captured the city, May 6, 1527.
Bourbon, the ablest general of Charles, but a traitor to his native
France, was struck by a musket-ball in climbing a ladder, and fell dead
in the moment of victory. The pope fled to the castle St. Angelo. The
soldiers, especially the Spaniards, deprived of their captain,
surpassed the barbarians of old in beastly and refined cruelty, rage
and lust. For eight days they plundered the papal treasury, the
churches, libraries, and palaces, to the extent of ten millions of
gold; they did not spare even the tomb of St. Peter and the corpse of
Julius II., and committed nameless outrages upon defenseless priests,
monks, and nuns. German soldiers marched through the streets in
episcopal and cardinal’s robes, dressed a donkey like
a priest, and by a grim joke proclaimed Luther as pope of Rome.

When the news reached Germany, many rejoiced, at
the fall of Babylon." But Melanchthon, rising above bigotry, said in
one of his finest addresses to the students of Wittenberg: "Why should
we not lament the fall of Rome, which is the common mother-city of all
nations? I indeed feel this calamity no less than if it were my own
native place. The robber hordes were not restrained by considerations
of the dignity of the city, nor the remembrance of her services for the
laws, sciences, and arts of the world. This is what we grieve over.
Whatever be the sins of the Pope, Rome should not be made to suffer."
He acquitted the Emperor of all blame, and held the army alone
responsible.940940 "Corp. Ref.," XI. 130; C. Schmidt, Phil.
Melanchthon, p. 135 sq.